This application requests funds for an Exploratory/ Developmental grant to design and prepare to implement a large multi-state study of infants with fragile X syndrome and their families. Based on a period of universal screening of approximately 1,000,000 newborns for FXS in selected states, the study would be designed to answer eight sets of research questions: (1) What is the incidence rate of FXS in the U.S.? Does this rate vary as a function of ethnicity? (2) How acceptable to the public is screening for FXS? What proportion of parents voluntarily participate in screening? What characteristics differentiate parents who choose not to participate? (3) What is the relative effectiveness and acceptability of different models for informing families about FXS status and supporting them in gaining information about the disorder and reproductive risk? (4) Does the bonding and attachment relationship between parents of children with FXS differ from that of parents of normally developing children or children with non-heritable disorders? (5) How does knowledge of reproductive risk affect subsequent reproductive decisions of parents of children with FXS? (6) What patterns of development characterize infants and toddlers with FXS? How do these patterns vary as a function of factors such as FMRP, physiological variables, SES, gender, and autism? (7) What is the efficacy of contrasting models of early intervention for children with FXS and their families? Does treatment efficacy vary in accordance with the severity and nature of disability? and (8) What patterns of coping and adaptation characterize families of children with FXS during the early years? How do these patterns vary as a function of child, parent, family, and ecological variables? A multi-university, multi-disciplinary team of investigators and consultants will determine the participating states and develop state-based planning teams; determine the laboratory procedure to be used for screening; identify and address a range of ethical and practical issues; develop a protocol and procedures for genetic counseling, family support, studies of family adaptation, studies of infant development, and studies of the efficacy of child and family intervention models; work with an array of agencies, organizations, and individuals to garner widespread support for the project and its implementation; and develop the infrastructure necessary to implement the study.